Compositions and coatings for uv-vis and ir transparent thin films

Abstract

Compositions and coatings for thin films designed to protect surfaces and windows from environmental abrasion (e.g., sand, dust, and rubbing) that are transparent in visual and infrared wavelengths are disclosed. The compositions comprise thiol-containing copolymers comprising: (1) 10-(3-butyl-2-hexyl-6-(9-mercaptononyl)cyclohexyl) decane-1-thiol; and (2) a multifunctional terminally unsaturated hydrocarbon monomer; wherein (1) and (2) are combined to form a UV curable crosslinked thermoset polymer network and no particulate fillers are added to the composition. The films exhibit a specular transmission of greater than 70% in the visual spectrum at about 400-700 nm, and IR wavelengths at about 4-5 μm, and about 7.5-12 μm when applied to a surface of a substrate in a coating thickness of about 1-500 μm. A method for making the films involving an UV initiated thiol-ene curing mechanism is also provided.

1 . A polymer composition comprising:
 a thiol-containing copolymer which comprises (1) 10-(3-butyl-2-hexyl-6-(9-mercaptononyl)cyclohexyl)decane-1-thiol; and (2) at least one multifunctional terminally unsaturated hydrocarbon monomer;   wherein (1) and (2) are combined to form a UV curable crosslinked thermoset polymer network, and particulate fillers are not added to the composition; and   wherein the composition exhibits a specular transmission of greater than 70% in a visual spectrum at about 400-700 nm, and IR wavelengths at about 4-5 μm, and about 7.5-12 μm when applied to a surface of a substrate in a coating thickness of about 1 to 500 μm.   
     
     
         2 . The polymer composition according to  claim 1 , wherein the thiol-containing copolymer further comprises (3) at least one multifunctional thiol-terminated hydrocarbon monomer comprising a hydrocarbon interior. 
     
     
         3 . The polymer composition according to  claim 1 , further comprising one or more of a solvent, an initiating agent, a pigment, a dye, an antioxidant, and a UV stabilizer. 
     
     
         4 . The polymer composition according to  claim 2 , wherein the multifunctional thiol-terminated hydrocarbon monomer is 2-[2,4-bis(2-mercaptoethyl)cyclohexyl]ethanethiol, 1,3,5, tris(2-mercaptoethyl)cyclohexane or α,ω-thiol-terminated hydrogenated polybutadiene, and mixtures thereof. 
     
     
         5 . The polymer composition according to  claim 1 , wherein the at least one multifunctional terminally unsaturated hydrocarbon monomer is 1,2,4-trivinylcyclohexane. 
     
     
         6 . The polymer composition according to  claim 1 , wherein the at least one multifunctional terminally unsaturated hydrocarbon monomer comprises 1,2,4-trivinylcyclohexane and polybutadiene. 
     
     
         7 . The polymer composition according to  claim 2 , wherein the at least one multifunctional thiol-terminated hydrocarbon monomer is 2-[2,4-bis(2-mercaptoethyl)cyclohexyl]ethanethiol, and the at least one multifunctional terminally unsaturated hydrocarbon monomer comprises 1,2,4-trivinylcyclohexane and polybutadiene. 
     
     
         8 . A film comprising a polymer composition which comprises:
 a thiol-containing copolymer which comprises (1) 10-(3-butyl-2-hexyl-6-(9-mercaptononyl)cyclohexyl)decane-1-thiol; and (2) at least one multifunctional terminally unsaturated hydrocarbon monomer;   wherein (1) and (2) are combined to form a UV curable crosslinked thermoset polymer network and particulate fillers are not added to the composition;   wherein said polymer composition is applied to a surface of a substrate and cured by UVC light or UV light to form the film; and   wherein the film exhibits a specular transmission of greater than 70% in a visual spectrum at about 400-700 nm, and IR wavelengths at about 4-5 μm, and about 7.5-12 μm when applied to a surface of a substrate in a coating thickness of about 1 to 500 μm.   
     
     
         9 . The film according to  claim 8 , wherein the thiol-containing copolymer further comprises (3) at least one multifunctional thiol-terminated hydrocarbon monomer comprising a hydrocarbon interior. 
     
     
         10 . The film according to  claim 8 , wherein the at least one multifunctional terminally unsaturated hydrocarbon monomer is 1,2,4-trivinylcyclohexane. 
     
     
         11 . The film according to  claim 8 , wherein the at least one multifunctional terminally unsaturated hydrocarbon monomer comprises 1,2,4-trivinylcyclohexane and polybutadiene. 
     
     
         12 . The film according to  claim 9 , wherein the thiol-containing copolymer comprises 10-(3-butyl-2-hexyl-6-(9-mercaptononyl)cyclohexyl)decane-1-thiol and (2-[2,4-bis(2-mercaptoethyl)cyclohexyl]ethanethiol), and the at least one multifunctional terminally unsaturated hydrocarbon monomer comprises 1,2,4-trivinylcyclohexane and polybutadiene. 
     
     
         13 . The film according to  claim 9 , wherein the film is further cured by exposure to electron beam radiation. 
     
     
         14 . The film according to any one of  claim 9 , wherein the polymer composition applied to the surface of the substrate is cured by UVC light or UV light without addition of an initiating agent. 
     
     
         15 . The film according to  claim 9 , wherein the polymer composition applied to the surface of the substrate is cured by UVC light or UV light with addition of a photoinitiator. 
     
     
         16 . A method for making a film comprising:
 providing a thiol-containing copolymer which comprises 10-(3-butyl-2-hexyl-6-(9-mercaptononyl)cyclohexyl)decane-1-thiol;   providing at least one multifunctional terminally unsaturated hydrocarbon monomer;   dissolving the thiol-containing copolymer which comprises 10-(3-butyl-2-hexyl-6-(9-mercaptononyl)cyclohexyl)decane-1-thiol and the at least one multifunctional terminally unsaturated hydrocarbon monomer in a solvent and forming a reaction mixture;   depositing the reaction mixture onto a surface of a substrate to form a coating; and   curing the coating with UVC light or UV light to form the film.   
     
     
         17 . The method according to  claim 16 , wherein the thiol-containing copolymer further comprises a multifunctional thiol-terminated hydrocarbon monomer. 
     
     
         18 . The method of  claim 16 , wherein the thiol-containing copolymer further comprises a monofunctional thiol-terminated hydrocarbon monomer or a monofunctional thiol-terminated hydrocarbon monomer. 
     
     
         19 . The method according to  claim 16 , further comprising, after forming a reaction mixture, partially reacting the thiol-containing copolymer and the at least one multifunctional terminally unsaturated hydrocarbon monomer in the reaction mixture by exposure to UVC light. 
     
     
         20 . The method according to  claim 16 , further comprising exposing the film to electron beam radiation. 
     
     
         21 . The method according to  claim 16 , wherein curing the coating with UVC light or UV light, includes addition of a photoinitiator, or (b) is without additional of an initiating agent. 
     
     
         22 . The method according to  claim 16 , wherein curing the coating with UVC light or UV light is without addition of an initiating agent. 
     
     
         23 . The method according to  claim 16 , wherein the at least one multifunctional terminally unsaturated hydrocarbon monomer is 1,2,4-trivinylcyclohexane. 
     
     
         24 . The method according to  claim 16 , wherein the at least one multifunctional terminally unsaturated hydrocarbon monomer comprises 1,2,4-trivinylcyclohexane and polybutadiene. 
     
     
         25 . The method according to  claim 17 , wherein the thiol-containing copolymer comprises 10-(3-butyl-2-hexyl-6-(9-mercaptononyl)cyclohexyl)decane-1-thiol (1) and 2-[2,4-bis(2-mercaptoethyl)cyclohexyl]ethanethiol, and the at least one multifunctional terminally unsaturated hydrocarbon monomer comprises 1,2,4-trivinylcyclohexane and polybutadiene. 
     
     
         26 . A window comprising a substrate and a thin film according to  claim 8  applied to a surface of the substrate.